Numerous types of mortice locks are known. A problem common to most known mortice locks is their inability to be easily re-configured to suit different door backset distances. This requires different models of each lock for each backset distance, which adds to development and inventory cost.
Another problem is a lack of space efficiency of the internal components. Compactness is vital, especially for short backset distances.
Further, many known mortice locks can only operate in one handle turning direction, which causes operational problems with knobs, as they tend to be used in both directions.
Some mortice locks have the locking cylinder above the handle. This results in keys scratching the handle. Also, the large opening in the housing where the cylinder is fitted, allows sawdust and other debris to fall in to the lock mechanism and cause mechanical failure.